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Transcript of [email protected] CP Violation: SM & Beyond Amarjit Soni HET,BNL ([email protected])[email protected]...
CP Violation: SM & Beyond
Amarjit Soni
HET,BNL
YITP@40
Outline
• I. (since ~’01) B-factories +lattice (WME) help us attain an important milestone
• II. (since ~’05) improved BF tests
are revealing interesting hints of BSM-CP-odd phase(s)
• III..Whodunit ?
[email protected] 5Youngjoon Kwon
[email protected] 6Youngjoon Kwon
Most bands dueTo theory errors
Atwood&A.S,hep-ph/0103197
1st Hints of confirmationOf CKM-CP violation
[email protected] 9Youngjoon Kwon
[email protected] 10Youngjoon Kwon
Celebration II: A beautiful theory paper which not only suggested the need for the3rd family, before the discovery of charm and tau, its framework is
vindicated in detail through exhaustive experimentation ~35 years later!!
Should 10% tests be good enough?
Vital Lessons from our past
• LESSON # 1: Remember εK
• Its extremely important to reflect on the severe and tragic consequences if
Cronin et al had decided in 1963 that O(10%) searches for ε were good enough!
Imagine what an utter disaster for our field that would have been. Note also even though CKM-CP-odd phase is O(1) (as we now know)in the SM due to this O(1) phase only in B-physics we saw large effects…in K (miniscule), D(very small), t(utterly negligible).
Understanding the fundamental SM parameters to accuracy only of O(10%) would leave us extremely vulnerable …..Improvement of our understanding should be our crucial HOLY GRAIL!
Lesson #2
Remember mν
Just as there was never any good reason for mν =0 there is none for BSM-CP-odd phase not to exist
Δm2 ~1eV2 ~ 1980 -> Δm2 ~10-4 eV2 …’97
Osc. Discovered….
Similarly for BSM-CP-odd phase, we may need to look for much smaller deviations than the current O(10%)
demanding precision from expt. & theory
Brief (~25 years) History of BK
, ~’83 DGH use K+ lifetime + LOChPT + SU(3)->BK ~0.33… no error estimate, no scale dependence….
~’84 Lattice method for WME born…many attempts& improvements for BK evaluations
~’98 JLQCDstaggered BK (2GeV)= 0.628(42)quenched(~110). ~’97 1st BK with DWQ(T.Blum&A.S),0.628(47) quenched.~’01 RBC BK with DWQ, quenched=0.532(11) quenched
~’05 RBC , nf=2, dyn. DWQ, BK =0.563(21)(39)(30)
~’06 Gimnez et al (HPQCD; stagg.) 2+1, BK =0.618(18)(19)(30)(130)
~07,RBC-UKQCD DWQ 2+1 …..0.557(12)(29)DWQ lower BK -> requiring larger CKM-phase
~’08 Target 2+1 dyn. DWQ, BK with total error 5%
II. A tale of four numbers
• Tantalizing (possible) signs of a
BSM-CP-odd phase
0.52±0.050.52±0.05
Current situation
• Reference value reduced to 0.68±0.03
• Average value from penguin modes increased to
• Deviation reduced to 2.8σ
New Physics in penguin processes?
Matthias Neubert
Although, at the moment it is not a conclusive effect, it may well become a serious blunder on the part
of experimentalists to ignore it!We can try learn some lessons from history.
It is extremely important to understandthat basically it is a very good test of the SM.
So far 3 numbers• Expt [εK , B-mixing, b->ueν…] + Lattice WME
-> sin2βSM =0.79+-0.10
• BF measurements [B -> “ψ” KS ]=0.674+-0.026
• BF measurements [B-> (φ, η’…) KS ]=0.52+-.05
• -> Deviations 2.8 -3.5 sigmas
Honest answer &
• Don’t really know (too many possibilities…)
• But theoretically the most interesting possibility is that we may be witnessing
Dawning of the age of
“Warped Quantum Flavordynamics”
B-Factory Signals for a WED(Agashe,Perez,Soni,hep-ph/0406101(PRL);0408
134 (PRD)
• RS with a WARPED EXTRA DIMENSION (WED) provides an elegant solution to the HP
• In this framework, due to warped higher-dimensional spacetime, the mass scales (i.e. flavors) in an effective 4D description depend on location in ED. Thus, e.g. the light fermions are localized near the Plank brane where the effective cut-off is much higher than TeV so that FCNC’s from HDO are greatly suppressed.. The top quark,on the other hand is localized on the TeV brane so that it gets a large 4D top Yukawa coupling.
Key features of WED
• Amielorating the Flavor Problem. This provides an understanding of hierarchy of fermion masses w/o hierarchies in fundamental 5D params. Thus “solving” the SM flavor problem.
Flavor violations Most flavor-violating effects arise due to the violation of RS-GIM mechanism by the large top mass.
This originates from the fact that (t,b)L is localized on the TeV brane.
NP Contributions due WED
There are essentially 3 types of top quark
dominated FCNC contributions:
i) Contributions to FCNC processes arise
from a relatively large dispersion in the
doublets 5D masses, specifically large coupling of (t,b)L to gauge modes due to
heaviness of the t.
ii) Contributions to FCNC processs (mostly semi-leptonic)
These arise from contribution of i) and mixing between the zero and KK states of the Z due to EWSB.
iii) Contribution to radiative B-decays via
dipole operators arise from large 5D Yukawa required to obtain mt
Summary & Outlook
• Results on TDCP asy. in B->ψKS from BF along with some existing exptal #s & lattice WME for
the 1st time give a striking quantitative confirmation of the CKM-paradigm of CPV to O (15%)
• More stringent experimental tests at BF now appear difficult to reconcile with the CKM-paradigm and hint at
the need for a BSM-CP-odd phase• Most interesting explanation: ONSET the era of
WARPED QUANTUM FLAVORDYNAMICS
